JPS6345503B2 - - Google Patents

Abstract

PURPOSE:To supply lubricating oil in proper quantities, by equipping a pump unit driven through rocking motion of a connecting rod to the inside of a piston and participating a working medium from the pump unit to a sliding part of the piston through a passage. CONSTITUTION:A pump unit 7 is equipped to the inside of a crown part in a piston 1. This pump unit 7 is constituted such that a piston 9 is inserted into a cylinder 8 provided to the upper part of a connecting rod 5 while a piston rod 10 is connected to the upper part of the rod 5 through a link 11. Then in case of lack of an oil quantity for lubrication of, for instance, a compression ring groove 3a of the piston rings 3, a hole 12 provided to the cylinder 8 is communicated to the groove 3a through a passage 13, further lubricating oil or the like is sucked into the cylinder 8 from a hole 14 provided to the peripheral wall of the cylinder 8, and the lubricating oil is positively supplied to the groove 3a.

Description

[Detailed description of the invention] The present invention relates to a piston structure for an internal combustion engine.

In the piston of an internal combustion engine, lubricating oil is supplied to the sliding parts of the piston ring and cylinder liner.
Either the lubricating oil is supplied from the outside, which is usually called cylinder lubrication, or the lubricating oil splashes on moving parts such as connecting rods in the crankcase and randomly lubricates the ring parts, or the nozzle is used from the engine lubricating oil supply pipe. The most common method is the so-called splash lubrication method, in which lubrication is sprayed onto the sliding surfaces.

The amount of oil that rises from the piston ring portion to the combustion chamber above due to the supply of lubricating oil to the sliding portion is mainly controlled by the oil ring that is a part of the ring.

By the way, controlling the amount of oil added to the combustion chamber using the conventional lubricating oil supply method described above may result in poor control due to the precision of the oil ring itself or wear of the ring, or due to deformation of the cylinder liner. It also becomes defective, causing abnormalities in the cylinder and engine. Moreover, there are also problems such as poor control progressing over time.

Furthermore, the upper part of the ring row forms the compression ring, but this part is close to the combustion chamber and is exposed to high explosion pressure and intense heat from combustion, making it extremely difficult to lubricate this part. Despite being extremely important, the lubrication situation is extremely severe as it must also meet the contradictory conditions of minimizing the amount of oil entering the combustion chamber as much as possible.

On the other hand, the compression ring has a sealing function to prevent the high-pressure gas inside the cylinder from escaping downward.In this case, in addition to its own tension, the compression ring also receives the gas pressure from the back of the explosion, and the compression force causes the ring and cylinder to It is necessary to keep the sliding surface of the liner tight. However, this back pressure is due to the action of gas passing through the small gap between the piston ring groove and the ring.
Due to the throttling effect of the gap, the activation of back pressure may be delayed and gas blow-by may occur on the sliding surface.

In view of the above points, the present invention provides a solution to the drawbacks of the current ring system by equipping a piston-cylinder type pump unit inside the piston, and applying the pressure of the working medium from the pump unit to the sliding surface. A rational sliding surface lubrication system has been completed.

Embodiments of the present invention will be described below with reference to the drawings.

1 is a piston, 2 is a cylinder liner, 3 is a piston ring, 4 is a cylinder liner sliding part, 5 is a connecting rod, and 6 is a piston pin, which are the main moving parts of the internal combustion engine.

In the present invention, a pump unit 7 is provided within the crown portion of the piston 1. This pump unit 7 is of a piston-cylinder type in which a piston 9 is slid into a cylinder 8 provided on the upper part of a connecting rod 5. A piston rod 10 is connected to the upper part of the connecting rod 5 via a link 11. The pump unit 7 is driven according to the oscillating motion of the pump unit 7 to generate pressurizing force or negative pressure depending on the structure of the pump unit 7.

FIG. 2 shows the basic configuration of the pump unit 7, and the movement of the link 11 causes the piston 9 to move from side to side within the cylinder 8, allowing the working medium to act on the required portion through the hole 12 provided in the cylinder 8. .

That is, if the amount of oil in the piston ring 3 is insufficient for the lubrication of the compression ring 3a, the compressor is pumped through the hole 12 provided in the cylinder 8 of the pump unit 7 through the passage 13, as shown in FIG. It communicates with the tension ring groove and also connects cylinder 8.
Lubricating oil is introduced into the cylinder 8 through the hole 14 provided in the peripheral wall.
Alternatively, it is configured to suck air containing oil mist from the crankcase.

In this way, in conjunction with the swinging of the connecting rod 5, the
When the pump unit 7 is driven according to the operating procedure shown in FIG. Even if there is a delay, the lubricating oil is transferred to the compression ring groove 3 near the top dead center of the piston, where the pressure inside the engine cylinder is high and the temperature conditions are the most severe.
It is something that can be actively supplied to a.

In order to improve the oil scrubbing effect of the oil ring 3b in the piston ring 3, a hole 12 provided in the cylinder 8 of the pump unit 7 as shown in FIG.
communicates with the oil ring groove via the passage 15,
Further, the structure is such that oil can be discharged from inside the cylinder through a hole 14 provided in the peripheral wall of the cylinder 8.

In this way, in conjunction with the swinging of the connecting rod 5, the
When the pump unit 7 is driven according to the operating procedure shown in (b), the suction force can actively suck and remove excess lubricating oil from the sliding part 4 when the oil film is thick from the center to the bottom of the piston stroke. This makes it possible to effectively prevent oil buildup. This also reduces the number of oil rings.

Further, as shown in FIG. 7, by applying the pressure of the working medium from the pump unit 7 to the piston body 17 through the passage 18, the piston body 17 is
7 can also be kept well lubricated.

As explained above, the piston structure of the internal combustion engine of the present invention is equipped with a pump unit driven by the rocking motion of the connecting rod inside the piston, and the pump unit and the piston sliding part are connected through the passage. involving the working medium from the pump unit,
During engine operation, lubricant is actively replenished to sliding parts that are lacking in lubricant, and excess lubricant that causes oil buildup in the combustion chamber is actively removed. As a result, the ideal supply of lubricating oil was achieved with just the right amount and shortage.Furthermore, by applying pressure on the working medium to the back of the piston ring, gas blow-by prevention and gas tightness were effective, and the number of piston rings was reduced. It also helps to reduce ring friction loss, which improves engine efficiency.Furthermore, by applying pressure of the working medium to the piston body, it maintains good lubrication of the piston body and prevents abnormalities between the piston and cylinder. prevent or
This is a new and useful invention that has advantages such as being useful for noise reduction.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a partial sectional view of the engine, and FIG. 2 being a sectional view of the pump unit.
Figure 3 is a sectional view of the main part of the lubricating oil pressurized supply configuration, Figure 4 A and B are explanatory diagrams of the same supply procedure, Figure 5 is a sectional view of the main part of the lubricant suction and removal configuration, and Figure 6 I , B are explanatory diagrams of the removal procedure, and FIG. 7 is a sectional view of a main part of the pressurized supply structure of lubricating oil to the piston body. . 1... Piston, 2... Cylinder liner, 3...
...Piston ring, 4...Cylinder liner sliding part, 5...Connecting rod, 6...Piston pin, 7...
Pump unit, 8... cylinder, 9... piston, 10... piston rod, 11... link,
12... hole, 13... passage, 14... hole, 15...
...Passage, 16...Check valve, 17...Piston body,
18...Aisle.

Claims (1)

[Claims] 1. A piston-cylinder type pump unit is provided inside the piston of an internal combustion engine, and the piston of the pump unit is connected to a connecting rod of the engine, and the cylinder working chamber of the piston unit is connected to the piston unit through a passage. A piston structure for an internal combustion engine, characterized in that the piston is connected to a sliding portion of the piston. 2. The pump unit generates pressurized pressure or negative pressure on a working medium such as working air or working fluid by driving, and supplies or supplies the working medium to the piston ring by applying this pressure to the piston ring. The piston structure for an internal combustion engine according to claim 1, characterized in that the piston structure performs suction. 3. The pump unit is characterized in that when driven, a pressurizing force is generated on a working medium such as working air or a working fluid, and the working medium is supplied to the piston body by applying this pressure to the piston body. A piston structure for an internal combustion engine according to claim 1.